/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.solr.search;

import java.net.URL;

import org.apache.solr.common.util.NamedList;
import org.apache.solr.common.util.SimpleOrderedMap;

import org.apache.solr.core.SolrCore;
import org.apache.solr.core.SolrInfoMBean;

import org.apache.lucene.search.FieldCache;
import org.apache.lucene.search.FieldCache.CacheEntry;
import org.apache.lucene.util.FieldCacheSanityChecker;
import org.apache.lucene.util.FieldCacheSanityChecker.Insanity;

/**
 * A SolrInfoMBean that provides introspection of the Lucene FiledCache, this is
 * <b>NOT</b> a cache that is manged by Solr.
 * 
 * 
 */
public class SolrFieldCacheMBean implements SolrInfoMBean {

	protected FieldCacheSanityChecker checker = new FieldCacheSanityChecker();

	public String getName() {
		return this.getClass().getName();
	}

	public String getVersion() {
		return SolrCore.version;
	}

	public String getDescription() {
		return "Provides introspection of the Lucene FieldCache, "
				+ "this is **NOT** a cache that is managed by Solr.";
	}

	public Category getCategory() {
		return Category.CACHE;
	}

	public String getSource() {
		return "$URL: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_0/solr/core/src/java/org/apache/solr/search/SolrFieldCacheMBean.java $";
	}

	public URL[] getDocs() {
		return null;
	}

	public NamedList getStatistics() {
		NamedList stats = new SimpleOrderedMap();
		CacheEntry[] entries = FieldCache.DEFAULT.getCacheEntries();
		stats.add("entries_count", entries.length);
		for (int i = 0; i < entries.length; i++) {
			CacheEntry e = entries[i];
			stats.add("entry#" + i, e.toString());
		}

		Insanity[] insanity = checker.check(entries);

		stats.add("insanity_count", insanity.length);
		for (int i = 0; i < insanity.length; i++) {

			/**
			 * RAM estimation is both CPU and memory intensive... we don't want
			 * to do it unless asked. // we only estimate the size of insane
			 * entries for (CacheEntry e : insanity[i].getCacheEntries()) { //
			 * don't re-estimate if we've already done it. if (null ==
			 * e.getEstimatedSize()) e.estimateSize(); }
			 **/

			stats.add("insanity#" + i, insanity[i].toString());
		}
		return stats;
	}

}
